This is post 6/? about the intersection of my decades of LW-style rationality practice and my several years of Zen practice.
In today's installment, I look at karma from a rationalist perspective.
Karma is one of those ideas that is poorly understood both because it means different things in different contexts and because there's a simple but bad abstraction of the idea that's easily understood and shared but points to something other than what we mean by "karma" in Zen, thus leading to bucket errors.
So, first, what is karma not. The Zen notion of karma is not any of the related ideas also called "karma" present in other dharmic traditions. It's also not the New Age or Theosophy notion of karma. All of these you are probably familiar with and might be expressed in one of the following ways:
In Zen (and some other Buddhist traditions), karma is nothing so involved. Instead, you can just read it as "causality" and you'll be 80% of the way of understanding it, with the remaining 20% some subtlety around how causal relationships relate to the fundamental flowing of one moment into the next that come from understanding how map and territory relate.
As you might guess, the other notions of karma relate to this one as heuristics about how earlier moments affect later ones. For example, the thread of moments out of which a person can be identified contain within them all the causes of the person's present condition, and it's often true that if you behave prosocially towards others they'll behave prosocially towards you, so a reasonable compression of karma that skips all the finer points look a lot like "if you do good stuff, good stuff will happen to you; if you do bad stuff, bad stuff will happen to you". Mix in some beliefs about reincarnation and you have karma as it is commonly encountered, bucket errors and all.
I don't like the concept of karma: as you say it gets reduced to "if you do good stuff, good stuff will happen to you; if you do bad stuff, bad stuff will happen to you". In other words, you deserve whatever happens to you. You can go around punching people in the face, they deserve it. And with reincarnation you can go around punching newborns because they must have done something wrong in previous life...